Mock.Object is slow for some types

[acesiddhu]

Hi Team

we are using Mock in our code base and we have noticed that Mock.Object call is slow for certain types. I have created a repro the issue here https://github.com/acesiddhu/MockHttpClients
Do we know why the call is slow? any thing we can do on our side to fix this issue?

[stakx]

@acesiddhu: The speed of accessing mock.Object for the first time for a given mock instance is mostly determined by the work done by the proxy library used (Castle DynamicProxy). Creating a proxy type will take longer the more members the mocked type has.

Will look at your repo at a later time but chances are there's generally not much you can do about perf.

[acesiddhu]

@stakx sure let me know. if there are any workaround we can try please suggest those as well

[stakx]

OK, judging from your repo, it seems that you have already figured out that new Mock<T>(...) is faster than Mock.Of.

You might already have noticed that SetupAllProperties isn't very fast (and it's called by Mock.Of behind the scenes).

If you want to increase mocking speed, you could define role interfaces for the capabilities used in e.g. GitHttpClient, and use dependency injection in your code base to inject the concrete type for the role interface. This would allow you (in your test code) to mock only the role interface instead of the actual concrete class. This should be faster because the role interface will in all likelihood contain only very few members (see my first comment above).

I don't have any further suggestions apart from that.